This is a uniquely valuable animal resource that provides the opportunity for a large number of investigators to study the interactions of aging, obesity, insulin resistance,and non-insulin dependent diabetes mellitus (NIDDM, Type II diabetes). This resource is unique in the large number of diabetic and pre-diabetic rhesus monkeys which are under longitudinal study.The importance of this colony lies in the large number of animals that have spontaneously developed obesity, often followed by the development of diabetes. Previous studies in this Center have provided evidence that this aging-associated diabetes in monkeys is extraordinarily similar to the human condition. This colony is presently in direct support of many extramural and intramural studies of interest to the NIA.